CMOV replaces branches. So no branch, no speculation. Typically, though, only branches that the compiler identifies as not reliably predictable would be replace

CMOV replaces branches. So no branch, no speculation. Typically, though, only branches that the compiler identifies as not reliably predictable would be replaced. Because with a well predicted branch you do not waste resources. CMOV executes both paths, wasting the work of one path, but saving the mispredict penalty. Which for “flakey” branches can be a overall win.